Geography revision notes on cities

Urbanisation - the process of the urban growth, whereby an increasing proportion of people live in urban areas (villages & countryside)

Urban Sprawl - The outward growth of urban areas.

What are the causes of urbanisation in developing countries?

Developing countries in rural urban migration.

Poor social and economic conditions in rural areas encourage people to move to urban areas where they may have more opportunities to access basic facilities.

The problem of natural disasters and lack of land ownership in rural areas further adds to the pressure to move to urban areas where there may be more employment opportunities and higher incomes.

Many migrants are aged between 15 and 35 years, so urban populations are often youthful, adding to the pressure of urban growth as a result of high birth rates.

Urbanisation in China

With rapid economic growth in recent years, china is experiencing high rates of urban growth as millions of migrants move towards newly developed industrial areas seeking work.

In 1950 New York was the only global megacity; by 2015 it is estimated that there will be 27 megacities, 21 of them in developing countries with the majority in Asia, the continent with the largest number of people living in urban areas.

Environmental hazards in urban areas

How does urban growth increase environmental pressures?

A growing demand on transport increases vehicle emissions

Increasing demand for energy leads to the building of power stations, which increases air pollution.

Air pollution in caused by burning firewood and coal in the growing urban slums in developing countries.

Water courses become increasingly polluted by industrial and human waste.

Waste is often burnt, creating additional toxic pollution, or it is left in growing waste dumps where it may pollute water systems.

As urban areas grow the rate of building increases, reducing the amount of green space.

Improving the urban environment

What are the main features of Curitiba's environmental management strategy?

A traffic-free city centre - Curitiba was the first Brazilian city to have pedestrianized streets.

A fully integrated bus system that is cheap and reliable - individual fuel use is 25% less than that in most urban areas in Brazil.

The development of green urban space - Parks, river walkways and cycle-tracks have been built. Over 1.5 million trees have been planted.

Recycling of buildings - old buildings are converted into new uses, saving resources and helping to maintain the character of the city.

A green exchange system - slim dwellers who collect garbage can exchange it for food or bus tickets. Children can exchange bags of collected garbage for toys or school supplies.

A public housing programme - the urban poor are given the opportunity to build basic homes. This ensures that most people have access to clean water and proper sanitation systems.

A recycling programme - 70% of rubbish is sorted, recycled and sold, reducing the need for landfill. The money earned is used to improve social facilities in the city.

Sustainable: meeting the needs of people without damaging the environments or exploiting resources.

Megacities

Dhaka - 500,000 people a year

Shanghai - Fastest growing city in the world

London

Tokyo

Mexico City

The threat and natural hazards in urban areas

A natural hazard is an event such as a flood, tropical storm, tsunami or earthquake only becomes a hazard when it affects people.

The reasons people move to urban areas in developing countries are described as push and pull factors. Safe water, education and healthcare in the urban population is what attracts people to the place.

Key terms:

Tsunami: tidal wave caused by an undersea earthquake.

Floodplain: a low-lying area next to a river that is vulnerable to flooding.